Malicious PDF — malware analysis report

Static analysis result for SHA-256 23df52e4cf86ec2c…

MALICIOUS

PDF

77.8 KB Created: 2021-09-09 10:37:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 85bdc65fe613289667de4ffe39d87ac3 SHA-1: 38864b8bdced8e458c71ebe7fc3b8ad5f0449893 SHA-256: 23df52e4cf86ec2cd3120dac9fba1b6b4cf6e34e3806f4bea83b8ebdce5fe634
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to potentially malicious domains, suggesting it functions as a link farm or phishing lure. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically indicates the document's structure is designed to host many links on disposable hosting, reinforcing the phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://chcial.ru/uplcv?utm_term=gallery+paid+apk PDF link annotation
    • http://srtcivilnorth.com/ckeditor_file/files/supulabibaremin.pdfIn PDF document text
    • http://myapartment.de/web/editor/files/gurunenuredirisiwujax.pdfIn PDF document text
    • http://ledlight-lamp.com/mingyi/images/userfiles/file/jores.pdfIn PDF document text
    • http://kapalishakti.com/ckfinder/userfiles/files/74408662372.pdfIn PDF document text
    • http://leaders-adv.net/userfiles/file/zetakefa.pdfIn PDF document text
    • http://www.stadion-zarya.ru/ckfinder/userfiles/files/bekizamefas.pdfIn PDF document text
    • http://rococosofa.com/files/files/mafirinoxekajibasiropeb.pdfIn PDF document text
    • https://activepymes.com/pub/file/laroxidusozezole.pdfIn PDF document text
    • http://videoacceso.com/wp-content/plugins/formcraft/file-upload/server/content/files/161332216ec1d7---18071210943.pdfIn PDF document text
    • http://www.mustwalge.ee/data/content/files/17996095226.pdfIn PDF document text
    • https://rumahbaruku.com/contents/files/1513074862.pdfIn PDF document text
    • http://franklcalabreseattorney.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/20978050579.pdfIn PDF document text
    • http://7linc.com/uploadfiles/fckeditor/20210901/file/16304557763358.pdfIn PDF document text
    • http://musicandyouapp.com/webupload/editorimg/files/67172761539.pdfIn PDF document text
    • http://haohanlegend.com/Uploadfiles/files/kifuwujopegunit.pdfIn PDF document text
    • http://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/41940525528.pdfIn PDF document text
    • http://wdnederland.nl/file/fetosijomodunatilug.pdfIn PDF document text
    • http://traktorpulling.de/ablage/userfiles/files/xibud.pdfIn PDF document text
    • http://xn----8sbfeahwarn6ac1adp3fb2p.xn--p1ai/userfiles/file/839790069.pdfIn PDF document text
    • http://tubesealer.com/uploaded/file/170946948561330356caad2.pdfIn PDF document text
    • http://russkiivopros.com/images/FCKeditor/file/32344427122.pdfIn PDF document text
    • https://marwaservicecenter.com/nbloom/fckuploads/file/nowadavumogigabobigoxi.pdfIn PDF document text
    • https://tauthuy.vn/upload/files/86927682012.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ccd4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCD4 10140 bytes
SHA-256: d9f5bbb9b476c989d078d724d00e7a65691f6fc1415d3ad31df3018116d99ef4
font_01_sfnt_off0000e393.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE393 17940 bytes
SHA-256: 911e38223528fe413a42acf5591b6cc206a2c20fa970c8054298f843b824fe6a
font_02_sfnt_off00011246.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11246 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1